Orthopedic braces are worn to lend support to a wearer for an injured or weakened joint such as a knee, shoulder, hip, elbow or ankle. Such braces provide support on either side of the joint so that the pivotal action of the joint occurs in a natural manner or as natural as possible. This natural manner permits muscles and ligaments to mend and strengthen.
Leg braces, particularly knee braces, have two arms with a mechanical joint between the arms. The mechanical joint is designed for multiple axis pivotal movement resembling the knee action as closely as possible.
One example of a mechanical joint for an orthopedic brace is disclosed in U.S. Pat. No. 3,902,482 which shows an orthopedic brace having arms attached to a wearer's body on opposite sides of a knee joint. There is a mechanical joint comprising a bearing plate on an end of each brace portion near the body joint and a link extending across the body joint has two bearing surfaces, one at each end, on which the bearing plates rest. The pivot connection between the bearing plates and the link provides a multiple axis pivotal movement as close as possible to the natural pivotal movement of the body joint.
The multiple axis pivotal movement of the brace disclosed in U.S. Pat. No. 3,902,482 results from two curved slots in the bearing plates with pins that extend through the slots and are attached to the two bearing surfaces of the link. It has been found that this brace has achieved excellent acceptance, because it takes up little space, is light and seemingly simple in construction and furthermore follows the relative complex motion of the knee unlike the braces that preceded it. However, the pin and slot operation of the pivot connection tends to wear and in some cases has a restricted or frictional movement when the slots are dragged across the pins as the mechanical joint moves between the flexed position and the extended position of the knee joint.